Semiconductor device

ABSTRACT

A semiconductor device includes an insulated circuit substrate, a semiconductor chip, a printed circuit board, an interposer, and a sealing member, the interposer including a plurality of post electrodes each having one end bonded to the semiconductor chip via a solder layer, an insulating layer provided to be separately opposed to the semiconductor chip and provided with a first penetration hole filled with part of the solder layer, and a conductor layer provided to be opposed to the printed circuit board and connected to another end of each of the post electrodes via the insulating layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of priority under 35 USC 119 based on Japanese Patent Application No. 2022-106480 filed on Jun. 30, 2022, the entire contents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a semiconductor device (a semiconductor module) equipped with power semiconductor chips.

2. Description of the Related Art

Power semiconductor chips (hereinafter, referred to simply as “semiconductor chips) are typically used as switching elements for power conversion.

JP 2022-22521 A discloses a semiconductor device including semiconductor chips provided on an insulated circuit substrate, a printed circuit board provided over the semiconductor chips, and interposers provided between the semiconductor chips and the printed circuit board, in which the respective interposers include an insulating layer, a conductor layer provided on the top surface of the insulating layer, and post electrodes connected to the bottom surface of the conductor layer.

JP 2021-82721 A discloses a semiconductor device including semiconductor chips provided on a stacked substrate, a printed circuit board provided over the semiconductor chips, and interposers provided between the semiconductor chips and the printed circuit board, in which the respective interposers include an insulating layer, post electrodes for emitter and for gate provided on one of the surfaces of the insulating layer opposed to the semiconductor chip, and a copper pattern for emitter serving as a main-electrode circuit layer and a copper pattern for gate serving as a control-electrode circuit layer each provided on the other surface of the insulating layer on the opposite side of the surface opposed to the semiconductor chip.

JP 2009-266986 A discloses a method of manufacturing a power conversion device including a step of executing solder bonding between signal terminals penetrating terminal penetration holes and connection terminals in a state in which a hole-provided insulating member is separated from a control circuit substrate. In the solder-bonding step, the solder when applied to opposite-side opening ends of the penetration holes passes through the through holes to reach main circuit-side opening ends due to a capillary phenomenon so as to rise and protrude.

JP 2000-228476 A discloses a semiconductor device with a configuration in which a solder-contact part of an outer lead can be provided with at least one slit or the solder-contact part of the outer lead can be provided with at least one penetration hole, and in particular, the penetration hole is used to serve as a surface-area increasing region, so as to allow a larger amount of solder to be supplied through the penetration hole further to the outer lead due to a capillary phenomenon, increasing the wettability of the solder accordingly.

JP H11-220070 A discloses a semiconductor device, in which cream-state solder melted by heat treatment is sucked into openings of small holes provided in an electrode terminal part bonded to an electrode pad due to a capillary phenomenon. While a copper-foil thickness of the electrode terminal part is about 35 micrometers, the small holes provided in the electrode terminal part can lead the solder to be sucked into the openings to further adhere to the top and bottom surfaces of the electrode terminal part, so as to ensure favorable and strong bonding conditions between the electrode terminal part and the electrode pad, as compared with a case of not being provided with any small holes in which the melted solder is led to adhere only to the bottom surface of the electrode terminal part.

JP 2020-155512 A discloses an interposer including an insulating plate-shaped member provided with an opening conforming to an outline of an electronic member, and a pair of electrodes interposing the opening and provided on one of the surfaces of the plate-shaped member.

JP2017-92185 A discloses a semiconductor device including a stacked substrate including an insulating plate and a circuit plate, a semiconductor chip with the front surface provided with a main electrode and a control electrode and with the rear surface fixed to the circuit plate, a first wired substrate including a first conductive member arranged to be opposed to and electrically connected to the first conductive member, a second wired substrate including a second conductive member arranged to be opposed to the control electrode and provided with an opening, and conductive posts having one ends electrically and mechanically connected to the control electrode and the other ends electrically and mechanically connected to the second conductive member, in which the first conductive member has a greater thickness than the second conductive member, and the first wired substrate is arranged inside the opening.

In the conventional semiconductor devices as disclosed in JP 2022-22521 A and JP 2021-82721 A, the solder creeps upward along the post electrodes of the interposers when the semiconductor chips and the interposers are bonded together via the solder, and the solder further spreads over the surfaces of the semiconductor chips. The creeping solder decreases gaps between the insulating layer of the respective interposers and the solder and thus prevents the sealing member from entering the gaps.

In addition, the spread of the solder increases the surface area of the solder to increase the contact area between the solder and the sealing member. Since the solder typically has bad adhesion to resin used for the sealing member, a binding force at the interface between the sealing member and the solder is decreased when a change in temperature is caused in the semiconductor device, which tends to apply a stress directly on the respective bonded parts and thus easily leads to separation or causes cracks. Further, the spreading solder could cause insulation failure if reaching the ends of the semiconductor chips.

SUMMARY OF THE INVENTION

In view of the foregoing problems, the present invention provides a semiconductor device having a configuration that can improve reliability and decrease insulation failure if a change in temperature is caused.

An aspect of the present invention inheres in a semiconductor device including: an insulated circuit substrate; a semiconductor chip deposited on one of main surfaces of the insulated circuit substrate; a printed circuit board provided to be opposed to the one of the main surfaces of the insulated circuit substrate; an interposer provided between the semiconductor chip and the printed circuit board; and a sealing member provided to seal the semiconductor chip, the interposer, and the printed circuit board, the interposer including a plurality of post electrodes each having one end bonded to the semiconductor chip via a solder layer, an insulating layer provided to be separately opposed to the semiconductor chip and provided with a first penetration hole filled with part of the solder layer, and a conductor layer provided to be opposed to the printed circuit board and connected to another end of each of the post electrodes via the insulating layer.

Another aspect of the present invention inheres in a semiconductor device including: an insulated circuit substrate; a semiconductor chip deposited on one of main surfaces of the insulated circuit substrate; a plurality of post electrodes each having one end bonded to the semiconductor chip via a solder layer; a printed circuit board provided to be opposed to the one of the main surfaces of the insulated circuit substrate; and a sealing member provided to seal the semiconductor chip and the printed circuit board, the printed circuit board including an insulating layer provided to be separately opposed to the semiconductor chip and provided with a first penetration hole filled with part of the solder layer, and a conductor layer connected to another end of each of the post electrodes via the insulating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view illustrating a semiconductor device according to a first embodiment;

FIG. 2 is a plan view illustrating an interposer in the semiconductor device according to the first embodiment;

FIG. 3 is a cross-sectional view as viewed from direction A-A in FIG. 2 ;

FIG. 4 is a cross-sectional view as viewed from direction B-B in FIG. 2 ;

FIG. 5 is a side view illustrating a semiconductor device of a comparative example;

FIG. 6 is a side view for explaining a method of manufacturing the semiconductor device according to the first embodiment;

FIG. 7 is a plan view illustrating an interposer in a semiconductor device according to a second embodiment;

FIG. 8 is a plan view illustrating an interposer in a semiconductor device according to a third embodiment;

FIG. 9 is a cross-sectional view as viewed from direction A-A in FIG. 8 ;

FIG. 10 is a plan view illustrating an interposer in a semiconductor device according to a fourth embodiment; and

FIG. 11 is a side view illustrating a semiconductor device according to a fifth embodiment.

DETAILED DESCRIPTION

With reference to the drawings, first to fifth embodiments of the present invention will be described below.

In the drawings, the same or similar elements are indicated by the same or similar reference numerals. The drawings are schematic, and it should be noted that the relationship between thickness and planer dimensions, the thickness proportion of each layer, and the like are different from real ones. Moreover, in some drawings, portions are illustrated with different dimensional relationships and proportions. The first to fifth embodiments described below merely illustrate schematically devices and methods for specifying and giving shapes to the technical idea of the present invention, and the span of the technical idea is not limited to materials, shapes, structures, and relative positions of elements described herein.

Additionally, definitions of directions such as upper and lower in the following description are simply definitions for convenience of description, and do not limit the technological concept of the present invention. For example, when observing an object rotated by 90 degrees, the upper and lower are converted to left and right to be read, and when observing an object rotated by 180 degrees, the upper and lower are read reversed, which should go without saying.

First Embodiment

A first embodiment is illustrated as a semiconductor device with a “1-in-1” power semiconductor module having functions for a single semiconductor element, as illustrated in FIG. 1 . The semiconductor device according to the first embodiment includes an insulated circuit substrate 1, semiconductor chips 3 a and 3 b deposited on one main surface (the top surface) of the insulated circuit substrate 1, a printed circuit board 6 opposed to the top surface of the insulated circuit substrate 1 and arranged over the respective semiconductor chips 3 a and 3 b, and interposers 5 a and 5 b provided to ensure a conductive connection between the respective semiconductor chips 3 a and 3 b and the printed circuit board 6. The top and side surfaces of the insulated circuit substrate 1, the semiconductor chips 3 a and 3 b, the interposers 5 a and 5 b, and the printed circuit board 6 are sealed with a sealing member 9.

The insulated circuit substrate 1 includes an insulating substrate 11, conductor layers (upper conductor layers) 12 a and 12 b deposited on the top surface side of the insulating substrate 11, and conductor layers (lower conductor layers) 13 a and 13 b deposited on the bottom surface side of the insulating substrate 11. The insulated circuit substrate 1 may be a direct copper bonded (DCB) substrate or an active metal brazed (AMB) substrate, for example. The insulating substrate 11 is a ceramic substrate made from alumina (Al₂O₃), aluminum nitride (AlN), or silicon nitride (Si₃N₄), or a resin insulating substrate including polymer material, for example. The upper conductor layers 12 a and 12 b and the lower conductor layers 13 a and 13 b are each conductor foil of metal such as copper (Cu) and aluminum (Al), for example.

The respective semiconductor chips 3 a and 3 b are deposited on the top surface of the upper conductor layer 12 a of the insulated circuit substrate 1 via bonding layers 2 a and 2 b made from solder or sintered material, for example. The semiconductor chips 3 a and 3 b as used herein can each be a metal-oxide-semiconductor field effect transistor including silicon (Si) (a Si-MOSFET) or a MOSFET using silicon carbide (SiC) (a SiC-MOSFET), for example, and the present embodiment is illustrated below with the case in which the semiconductor chips 3 a and 3 b are each a Si-MOSFET.

The semiconductor chips 3 a and 3 b each have a rectangular planar pattern, for example. The respective semiconductor chips 3 a and 3 b have a size of about 10 millimeters×10 millimeters, for example, but the size may be determined as appropriate. The respective semiconductor chips 3 a and 3 b have a thickness of about 100 micrometers, for example, but the thickness may be determined as appropriate. Although not illustrated in FIG. 1 , the semiconductor chips 3 a and 3 b each include a control electrode (a gate electrode) and a first main electrode (a source electrode) on the top surface side, and a second main electrode (a drain electrode) on the bottom surface side.

While the present embodiment is illustrated in FIG. 1 with the case in which the two semiconductor chips 3 a and 3 b are provided, the number of the semiconductor chips to be provided may be changed as appropriate depending on a current capacity of the semiconductor module, for example, and the semiconductor device according to the present embodiment may include a single semiconductor chip or may include three or more semiconductor chips.

The interposers 5 a and 5 b are arranged on the top surfaces of the corresponding semiconductor chips 3 a and 3 b via solder layers 8 a to 8 d. The solder layers 8 a to 8 d are each made from lead-free solder such as tin-antimony-based (Sn—Sb), tin-copper-based (Sn—Cu), tin-copper-silver-based (Sn—Cu—Ag), tin-silver-based (Sn—Ag), tin-silver-copper-based (Sn—Ag—Cu), tin-silver-bismuth-copper-based (Sn—Ag—Bi—Cu), tin-indium-silver-bismuth-based (Sn—In—Ag—Bi), tin-zinc-based (Sn—Zn), tin-zinc-bismuth-based (Sn—Zn—Bi), tin-bismuth-based (Sn—Bi), or tin-indium-based (Sn—In) solder, or leaded solder such as tin-lead-based (Sn—Pb) solder, for example.

The respective interposers 5 a and 5 b are provided to correspond to the respective semiconductor chips 3 a and 3 b. The use of the interposers 5 a and 5 b for the conductive connection between the respective semiconductor chips 3 a and 3 b and the printed circuit board 6 can reliably ensure the bonding between the respective semiconductor chips 3 a and 3 b and the printed circuit board 6 if the deposited positions of the semiconductor chips 3 a and 3 b are displaced, as compared with a case of not using any interposers but using post electrodes for ensuring the conductive connection between the respective semiconductor chips 3 a and 3 b and the printed circuit board 6.

FIG. 2 is a plan view of the interposer 5 a illustrated in FIG. 1 . FIG. 2 schematically indicates, by the broken lines, penetration holes 55 a to 55 j provided in an insulating layer 53 a hidden below conductor layers 54 a and 54 b, and post electrodes 51 a to 51 j serving as conductor members penetrating the penetration holes 55 a to 55 j. FIG. 3 is a cross-sectional view illustrating the circumferential elements of the interposer 5 a taken along line A-A in FIG. 2 , and FIG. 4 is a cross-sectional view illustrating the circumferential elements of the interposer 5 a taken along line B-B in FIG. 2 .

As illustrated in FIGS. 3 and 4 , the semiconductor chip 3 a includes a source electrode 31 and a gate electrode 32 on the top surface side. As illustrated in FIG. 1 to FIG. 4 , the interposer 5 a includes the insulating layer 53 a separately opposed to the top surface of the semiconductor chip 3 a, the conductor layers 54 a and 54 b deposited on the top surface of the insulating layer 53 a, and the post electrodes 51 a to 51 j connected to the respective bottom surfaces of the conductor layers 54 a and 54 b through the penetration holes 55 a to 55 j provided in the insulating layer 53 a.

The material to be used for the insulating layer 53 a can be resin such as polyimide, for example. The material to be used for the respective conductor layers 54 a and 54 b can be metal material such as copper (Cu), for example. The respective post electrodes 51 a to 51 j have a stick-like (a pin-like) or columnar shape, and in particular, may be a round column, a cylindroid, or a polygonal column such as a triangular column or a quadrangular column, for example. The respective post electrodes 51 a to 51 j may be projection electrodes (bumps). The material to be used for the respective post electrodes 51 a to 51 j can be metal material such as copper (Cu) or gold (Au), for example.

A length of the respective post electrodes 51 a to 51 j is in a range of about 0.5 millimeters or greater and 1.5 millimeters or shorter, for example, but may be determined as appropriate. A diameter of the respective post electrodes 51 a to 51 j is in a range of about 0.3 millimeters or greater and 1 millimeter or shorter, for example, but may be determined as appropriate.

As illustrated in FIG. 1 to FIG. 3 , the respective lower ends of the post electrodes for source 51 a to 51 i, among the post electrodes 51 a to 51 j, are bonded to the source electrode 31 of the semiconductor chip 3 a via the solder layer 8 a. The respective upper ends of the post electrodes 51 a to 51 i are connected to the conductor layer 54 a. The post electrodes 51 a to 51 i are arranged into a 3×3 matrix. A pitch of the matrix of the post electrodes 51 a to 51 i is set in a range of about 1 millimeter or greater and 2 millimeters or smaller, for example, but may be determined as appropriate. The number and the arranged positions of the post electrodes 51 a to 51 i are not limited to those as illustrated. The lower end of the post electrode for gate 51 j is bonded to the gate electrode 32 of the semiconductor chip 3 a via the solder layer 8 b. The upper end of the post electrode 51 j is connected to the conductor layer 54 b.

As illustrated in FIG. 1 to FIG. 4 , the insulating layer 53 a is further provided with penetration holes 56 a to 56 d, in addition to the penetration holes 55 a to 55 i through which the post electrodes 51 a to 51 i penetrate, between the respective post electrodes 51 a to 51 i and the respective penetration holes 55 a to 55 j. FIG. 1 schematically indicates the penetration holes 56 a and 56 b hidden by the side surface of the insulating layer 53 a. FIG. 2 schematically indicates, by the dashed and dotted lines, the penetration holes 56 a to 56 d hidden under the conductor layer 54 a. The penetration holes 56 a to 56 d penetrate the insulating layer 53 a so as to lead the bottom surface of the conductor layer 54 a to be exposed.

As illustrated in FIG. 2 , the penetration hole 56 a is provided separately from the respective post electrodes 51 a, 51 b, 51 d, and 51 e at the equal distances. The penetration hole 56 b is provided separately from the respective post electrodes 51 b, 51 c, 51 e, and 51 f at the equal distances. The penetration hole 56 c is provided separately from the respective post electrodes 51 d, 51 e, 51 g, and 51 h at the equal distances. The penetration hole 56 d is provided separately from the respective post electrodes 51 e, 51 f, 51 h, and 51 i at the equal distances. The respective arranged positions of the penetration holes 56 a to 56 d are not limited to those as illustrated, and are only required to be located between the respective post electrodes 51 a to 51 i.

While FIG. 2 illustrates the case in which the penetration holes 56 a to 56 d each have a circular planar pattern that is the same as the respective penetration holes 55 a to the shape of the penetration holes 56 a to 56 d may be determined as appropriate and may be different from the shape of the penetration holes 55 a to 55 j. The respective penetration holes 56 a to 56 f may have a triangular, rectangular, or oval planar pattern, for example. While FIG. 2 illustrates the case in which the respective penetration holes 56 a to 56 d have the same size as the respective penetration holes 55 a to 55 j, the respective penetration holes 56 a to 56 d may have a size different from that of the penetration holes 55 a to 55 j, and may have either a greater size or a smaller size than the penetration holes 55 a to 55 j. While FIG. 2 illustrates the case of including the four penetration holes 56 a to 56 d, the number of the penetration holes to be provided is not limited to that as illustrated, and may be changed as appropriate depending on the number or the density of the post electrodes 51 a to 51 i.

The respective penetration holes 56 a to 56 d are filled with part of the solder layer 8 a for bonding the source electrode 31 of the semiconductor chip 3 a to the respective post electrodes 51 a to 51 i. The solder of the solder layer 8 a during the heat treatment for bonding the source electrode 31 of the semiconductor chip 3 a to the respective post electrodes 51 a to 51 i creeps upward along the post electrodes 51 a to 51 i and enters the penetration holes 56 a to 56 d due to a capillary phenomenon to further reach the conductor layer 54 a. The solder layer 8 a is also provided between the respective post electrodes 51 a to 51 i.

The interposer 5 b illustrated in FIG. 1 has a configuration similar to that of the interposer 5 a. As illustrated in FIG. 1 , the interposer 5 b includes the insulating layer 53 b separately opposed to the semiconductor chip 3 b, the conductor layers 54 c and 54 d deposited on the top surface of the insulating layer 53 b, and the post electrodes 52 a to 52 c and 52 j penetrating the insulating layer 53 b and connected to the respective bottom surfaces of the conductor layers 54 c and 54 d.

The respective lower ends of the post electrodes 52 a to 52 c for source, among the post electrodes 52 a to 52 c and 52 j, are bonded to a source electrode (not illustrated) of the semiconductor chip 3 b via the solder layer 8 c. The respective upper ends of the post electrodes 52 a to 52 c are connected to the conductor layer 54 c. The lower end of the post electrode 52 j for gate is bonded to a gate electrode (not illustrated) of the semiconductor chip 3 b via the solder layer 8 d. The upper end of the post electrode 52 j is connected to the conductor layer 54 d.

The insulating layer 53 b is further provided with penetration holes 57 a and 57 b, in addition to penetration holes (not illustrated) through which the post electrodes 52 a to 52 c penetrate, between the post electrodes 52 a to 52 c. FIG. 1 schematically indicates the penetration holes 57 a and 57 b hidden by the side surface of the insulating layer 53 b. The respective penetration holes 57 a and 57 b are filled with part of the solder layer 8 c for bonding the source electrode (not illustrated) of the semiconductor chip 3 b to the respective post electrodes 52 a to 52 c.

The printed circuit board 6 is arranged over the semiconductor chips 3 a and 3 b via the interposers 5 a and 5 b, as illustrated in FIG. 1 . The printed circuit board 6 includes an insulating layer 61, conductor layers (upper conductor layers) 62 a and 62 b deposited on the top surface side of the insulating layer 61, and conductor layers (lower conductor layers) 63 a to 63 d deposited on the bottom surface side of the insulating layer 61.

The insulating layer 61 is made from insulating material such as ceramic or resin mainly including alumina (Al₂O₃), aluminum nitride (AlN), or silicon nitride (Si₃N₄), for example. The insulating layer 61 may be a resin substrate made from polyimide resin or a combination of glass fiber and epoxy resin, for example.

The upper conductor layers 62 a and 62 b and the lower conductor layers 63 a to 63 d are each conductor foil of metal such as copper (Cu) and aluminum (Al), for example. The upper conductor layers 62 a and 62 b and the lower conductor layers 63 a to 63 d may be plated with copper (Cu), nickel (Ni), or tin (Sn), for example.

The lower conductor layer 63 a is bonded to the conductor layer 54 a of the interposer 5 a via a bonding layer (not illustrated) made from solder or sintered material, for example. The lower conductor layer 63 b is bonded to the conductor layer 54 b of the interposer 5 a via a bonding layer (not illustrated) made from solder or sintered material, for example. The lower conductor layer 63 c is bonded to the conductor layer 54 c of the interposer 5 b via a bonding layer (not illustrated) made from solder or sintered material, for example. The lower conductor layer 63 d is bonded to the conductor layer 54 d of the interposer 5 b via a bonding layer (not illustrated) made from solder or sintered material, for example.

The upper conductor layer 62 a is electrically connected to the respective lower conductor layers 63 a and 63 c via conductor members (not illustrated) provided in penetration holes penetrating the insulating layer 61. The upper conductor layer 62 b is electrically connected to the respective lower conductor layers 63 b and 63 d via conductor members (not illustrated) provided in penetration holes penetrating the insulating layer 61.

A source-side connection terminal 7 a is inserted to the printed circuit board 6 to penetrate through the upper conductor layer 62 a, the insulating layer 61, and the lower conductor layer 63 a of the printed circuit board 6. The source-side connection terminal 7 a is made from metal material such as copper (Cu), for example. The lower end of the source-side connection terminal 7 a is bonded to the upper conductor layer 12 b of the insulated circuit substrate 1 via a bonding layer (not illustrated) made from solder or sintered material, for example. The upper end of the source-side connection terminal 7 a projects from the top surface of the sealing member 9 so as to be connected to an external circuit. The source-side connection terminal 7 a leads current from the source electrode 31 of the semiconductor chip 3 a and the source electrode (not illustrated) of the semiconductor chip 3 b to be supplied to the external circuit through the respective interposers 5 a and 5 b and the printed circuit board 6.

The lower end of a gate connection terminal 7 b is bonded to the upper conductor layer 62 b of the printed circuit board 6 via a bonding layer (not illustrated) made from solder or sintered material, for example. The gate connection terminal 7 b is made from metal material such as copper (Cu), for example. The upper end of the gate connection terminal 7 b projects from the top surface of the sealing member 9 so as to be connected to the external circuit. The gate connection terminal 7 b supplies control signals for controlling ON-OFF operations of the respective semiconductor chips 3 a and 3 b to the gate electrode 32 of the semiconductor chip 3 a and the gate electrode (not illustrated) of the semiconductor chip 3 b through the printed circuit board 6 and the respective interposers 5 a and 5 b.

The lower end of the drain-side connection terminal 7 c is connected to the upper conductor layer 12 a of the insulated circuit substrate 1 via a bonding layer (not illustrated) made from solder or sintered material, for example. The drain-side connection terminal 7 c is made from metal material such as copper (Cu), for example. The upper end of the drain-side connection terminal 7 c projects from the top surface of the sealing member 9 so as to be connected to the external circuit. The drain-side connection terminal 7 c leads current to be supplied to the respective drain electrodes (not illustrated) of the semiconductor chips 3 a and 3 b via the upper conductor layer 12 a.

The circumferences of the semiconductor chips 3 a and 3 b, the interposers 5 a and 5 b, and the printed circuit board 6 are sealed with the sealing member 9 so as to be electrically insulated from the other peripheral elements. The insulated circuit substrate 1 is exposed on the bottom surface of the sealing member 9. The sealing member 9 may be made from resin material such as thermosetting resin, and specific examples include epoxy resin, maleimide resin, and cyanate resin.

Comparative Example

A semiconductor device of a comparative example is described below. The semiconductor device of the comparative example differs from the semiconductor device according to the first embodiment illustrated in FIG. 1 in that the insulating layers 53 a and 53 b of the interposers 5 a and 5 b are provided only with the penetration holes (not illustrated) through which the post electrodes 51 a to 51 c and 52 a to 52 c penetrate, but are not provided with the through holes to be filled with part of the respective solder layers 8 a and 8 c included in the semiconductor device according to the first embodiment as illustrated in FIG. 1 .

In the semiconductor device of the comparative example, the solder of the solder layers 8 a and 8 b creeps upward along the post electrodes 51 a to 51 c and 52 a to 52 c of the interposers 5 a and 5 b when the semiconductor chips 3 a and 3 b are bonded to the interposers 5 a and 5 b via the solder layers 8 a to 8 d, and gaps 81 to 84 thus may be caused between the insulating layers 53 a and 53 b of the interposers 5 a and 5 b and the solder layers 8 a and 8 c, which prevents the entrance of the sealing member 9 if the gaps 81 to 84 are narrow. In addition, since the comparative example tends to increase the width W2 of the range in which the respective solder layers 8 a and 8 c spread over the respective surfaces of the semiconductor chips 3 a and 3 b, the surface areas of the solder layers 8 a and 8 c are also increased, and the contact surfaces between the solder layers 8 a and 8 c and the sealing member 9 are inevitably increased.

During the operation of the semiconductor device of the comparative example, a binding force at the interface between the sealing member 9 and the respective solder layers 8 a and 8 c is decreased if a change in temperature such as a heat cycle or a power cycle is caused in the semiconductor device, which tends to apply a stress directly on the respective bonded parts and thus easily leads to separation or causes cracks. Further, the solder layers 8 a and 8 c spreading over the surfaces of the semiconductor chips 3 a and 3 b could also cause insulation failure if reaching the ends of the semiconductor chips 3 a and 3 b.

The semiconductor device according to the first embodiment has the configuration as described above that differs from the semiconductor device of the comparative example in that the insulating layers 53 a and 53 b of the interposers 5 a and 5 b are provided with the penetration holes 56 a to 56 d, 57 a, and 57 d penetrating the insulating layers 53 a and 53 b to lead the conductor layers 54 a and 54 c to be exposed between the respective post electrodes 51 a to 51 i and 52 a to 52 c, as illustrated in FIG. 1 to FIG. 4 . Since the penetration holes 56 a to 56 d, 57 a, and 57 d lead the solder of the solder layers 8 a and 8 c to be drawn upward due to a capillary phenomenon when the semiconductor chips 3 a and 3 b are bonded to the interposers 5 a and 5 b via the solder layers 8 a to 8 d, an extra part of the solder layers 8 a and 8 c creeps upward along the post electrodes 51 a to 51 i and 52 a to 52 c and further enters the respective penetration holes 56 a to 56 d, 57 a, and 57 b. This can avoid a cause of gaps between the solder layers 8 a and 8 c and the insulating layers 53 a and 53 b. Further, since the extra part of the solder layers 8 a and 8 c tends to be concentrated in the center of the post electrodes 51 a to 51 i and 52 a to 52 c, the width W1 (refer to FIG. 1 ) of the range in which the solder layers 8 a and 8 c spread over the respective surfaces of the semiconductor chips 3 a and 3 b can be decreased, avoiding the expansion of the spreading area of the solder layers 8 a and 8 b. This configuration can improve the reliability and avoid or decrease the insulation failure of the semiconductor device according to the first embodiment if a change in temperature is caused.

<Method of Manufacturing Semiconductor Device>

A method of manufacturing (assembling) the semiconductor device according to the first embodiment is described below with reference to FIG. 6 . The insulated circuit substrate 1 is prepared first, and the respective semiconductor chips 3 a and 3 b are then deposited on the insulated circuit substrate 1 with the respective bonding layers 2 a and 2 b interposed. The solid-state solder layers 8 a to 8 d formed into a plate shape are further deposited on the semiconductor chips 3 a and 3 b.

The interposers 5 a and 5 b are also prepared so as to be deposited on the semiconductor chips 3 a and 3 b with the solder layers 8 a to 8 d interposed. A method of preparing the interposer 5 a is as follows: the penetration holes 55 a to 55 j through which the post electrodes 51 a to 51 j penetrate and the penetration holes 55 a to 56 d filled with part of the solder layer 8 a are formed in the insulating layer 53 a in a film-like state by use of a metal die. A conductor foil is then attached to the insulating layer 53 a, and is then delineated by etching or the like so as to form the conductor layers 54 a and 54 b. Alternatively, the conductor layers 54 a and 54 b may be preliminarily formed by etching or the like so as to be attached to the insulating layer 53 a in the film-like state. The conductor layers 54 a and 54 b are then subjected to plating treatment, and the post electrodes 51 a to 51 j are inserted by pressure into the penetration holes 55 a to 55 j of the insulating layers 53 a and 53 b, so as to prepare the interposer 5 a. The method of preparing the interposer 5 b includes the same steps of preparing the interposer 5 a described above.

The printed circuit board 6 is also prepared so as to be deposited on the respective interposers 5 a and 5 b with bonding layers (not illustrated) such as solder or sintered material interposed. Although not illustrated in FIG. 6 , the source-side connection terminal 7 a illustrated in FIG. 1 is inserted to the printed circuit board 6 so as to be deposited on the insulated circuit substrate 1 with bonding layers (not illustrated) such as solder or sintered material interposed. Similarly, the gate connection terminal 7 b illustrated in FIG. 1 is deposited on the printed circuit board 6 with bonding layers (not illustrated) such as solder or sintered material interposed. Similarly, the drain-side connection terminal 7 c illustrated in FIG. 1 is deposited on the insulated circuit substrate 1 with bonding layers (not illustrated) such as solder or sintered material interposed.

Next, a stacked body of the insulated circuit substrate 1, the semiconductor chips 3 a and 3 b, the interposers 5 a and 5 b, and the printed circuit board 6 is put into a heating furnace. The stacked body is then subjected to heating treatment in the heating furnace so that the insulated circuit substrate 1, the semiconductor chips 3 a and 3 b, the interposers 5 a and 5 b, the printed circuit board 6, the source-side connection terminal 7 a, the gate connection terminal 7 b, and the drain-side connection terminal 7 c are bonded together. The solder layers 8 a and 8 c for bonding between the semiconductor chips 3 a and 3 b and the interposers 5 a and 5 b are melted during this heat treatment, and the melted solder layers 8 a and 8 c then creep upward along the post electrodes 51 a to 51 i and 52 a and 52 c and are drawn further toward the penetration holes 56 a to 56 d, 57 a, and 57 b provided in the insulating layers 53 a and 53 b of the interposers 5 a and 5 b due to the capillary phenomenon. The penetration holes 56 a to 56 d, 57 a, and 57 b are then filled with the drawn-up solder of the solder layers 8 a and 8 b, and the solder layers 8 a and 8 b are concentrated in the center of the post electrodes 51 a to 51 i and 52 a to 52 c, so as to avoid the spread over the surfaces of the semiconductor chips 3 a and 3 b.

Thereafter, the semiconductor chips 3 a and 3 b, the interposers 5 a and 5 b, and the printed circuit board 6 are sealed with the sealing member 9. The semiconductor device illustrated in FIG. 1 is thus completed.

Second Embodiment

A semiconductor device according to a second embodiment differs from the semiconductor device according to the first embodiment in that the penetration holes 56 a to 56 d of the insulating layer 53 a of the interposer 5 a filled with part of the solder layer 8 a have a greater size than the penetration holes 55 a to 55 i through which the post electrodes 51 a to 51 i penetrate, and the respective penetration holes 56 a to 56 d are in contact with the penetration holes 55 a to 55 i and the post electrodes 51 a to 51 i, as illustrated in FIG. 7 .

The penetration hole 56 a is in contact with the penetration holes 55 a, 55 b, 55 d, and 55 e and the post electrodes 51 a, 51 b, 51 d, and 51 e. The penetration hole 56 b is in contact with the penetration holes 55 b, 55 c, 55 e, and 55 f and the post electrodes 51 b, 51 c, 51 e, and 51 f. The penetration hole 56 c is in contact with the penetration holes 55 d, 55 e, 55 g, and 55 h and the post electrodes 51 d, 51 e, 51 g, and 51 h. The penetration hole 56 d is in contact with the penetration holes 55 e, 55 f, 55 h, and 55 i and the post electrodes 51 e, 51 f, 51 h, and 51 i. The interposer 5 b illustrated in FIG. 1 also has a configuration similar to that of the interposer 5 a illustrated in FIG. 7 . The other configurations of the semiconductor device according to the second embodiment are the same as those of the semiconductor device according to the first embodiment, and overlapping explanations are not repeated below.

The semiconductor device according to the second embodiment, in which the penetration holes 56 a to 56 d of the insulating layer 53 a of the interposer 5 a are in contact with the penetration holes 55 a to 55 i and the post electrodes 51 a to 51 i, can also lead the solder layer 8 a to be drawn up through the penetration holes 56 a to 56 d due to the capillary phenomenon, so as to prevent a cause of gaps between the solder layer 8 a and the insulating layer 53 a and thus avoid the spread of the solder layer 8 a. This configuration can improve the reliability and avoid or decrease the insulation failure of the semiconductor device according to the second embodiment if a change in temperature is caused.

Third Embodiment

FIG. 8 is a plan view illustrating an interposer 5 a of a semiconductor device according to a third embodiment, and FIG. 9 is a cross-sectional view illustrating the circumferential elements of the interposer 5 a taken along line A-A in FIG. 8 . As illustrated in FIG. 8 and FIG. 9 , the semiconductor device according to the third embodiment differs from the semiconductor device according to the first embodiment in that the post electrodes 51 a to 51 i penetrate through the penetration holes 56 a to 56 i provided in the insulating layer 53 a of the interposer 5 a, and the gaps between the post electrodes 51 a to 51 i and the penetration holes 56 a to 56 i are filled with part of the solder layer 8 a.

The semiconductor device according to the third embodiment includes the penetration holes 56 a to 56 i through which the post electrodes 51 a to 51 i penetrate to protrude so as to lead the solder layer 8 a to be drawn up due to the capillary phenomenon. The penetration holes 56 a to 56 i have a greater size than the post electrodes 51 a to 51 i, and are separated from the post electrodes 51 a to 51 i. The outer circumferential surfaces of the respective post electrodes 51 a to 51 i may be partly in contact with the respective penetration holes 56 a to 56 i.

As illustrated in FIG. 9 , the conductor layer 54 a is provided with recesses 57 d to 57 f corresponding to the post electrodes 51 d to 51 f. The post electrodes 51 d to 51 f are inserted by pressure into the recesses 57 d to 57 f. Although not illustrated, the conductor layer 54 a is further provided with other recesses corresponding to the post electrodes 51 a to 51 c and 51 g to 51 i. The interposer 5 b illustrated in FIG. 1 also has a configuration similar to that of the interposer 5 a illustrated in FIG. 8 and FIG. 9 . The other configurations of the semiconductor device according to the third embodiment are the same as those of the semiconductor device according to the first embodiment, and overlapping explanations are not repeated below.

The semiconductor device according to the third embodiment, in which the gaps between the penetration holes 56 a to 56 i and the post electrodes 51 a to 51 i lead the solder layer 8 a to be drawn up due to the capillary phenomenon, can prevent a cause of gaps between the solder layer 8 a and the insulating layer 53 a and thus avoid the expansion of the spread of the solder layer 8 a. This configuration can improve the reliability and avoid or decrease the insulation failure of the semiconductor device according to the third embodiment if a change in temperature is caused.

In addition, the semiconductor device according to the third embodiment with the configuration described above can decrease the areas of the penetration holes 56 a to 56 i of the insulating layer 53 a, as compared with a case in which the penetration holes through which the post electrodes 51 a to 51 i penetrate are provided separately from the penetration holes filled with part of the solder layer 8 a, so as to improve the rigidity of the insulating layer 53 a.

Fourth Embodiment

A semiconductor device according to a fourth embodiment differs from the semiconductor device according to the first embodiment in that two post electrodes 51 j and 51 k for gates penetrate through the insulating layer 53 b of the interposer 5 a, and a penetration hole 56 e filled with part of the solder layer 8 b is provided between the two post electrodes 51 j and 51 k, as illustrated in FIG. 10 .

The insulating layer 53 b is provided with the penetration hole 56 e that leads the solder layer 8 b to be drawn up between the respective penetration holes 55 j and 55 k, in addition to penetration holes 55 j and 55 k through which the two post electrodes 51 j and 51 k penetrate. The interposer 5 b illustrated in FIG. 1 also has a configuration similar to that of the interposer 5 a illustrated in FIG. 10 . The other configurations of the semiconductor device according to the fourth embodiment are the same as those of the semiconductor device according to the first embodiment, and overlapping explanations are not repeated below.

The semiconductor device according to the fourth embodiment with the configuration regarding the insulating layer 53 a for source can lead the solder layer 8 a to be drawn up through the penetration holes 56 a to 56 d due to the capillary phenomenon, so as to prevent a cause of gaps between the solder layer 8 a and the insulating layer 53 a and thus avoid the expansion of the spread of the solder layer 8 a. The configuration regarding the insulating layer 53 b for gate, which is provided with the penetration hole 5 e between the respective post electrodes 51 j and 51 k, can lead the solder layer 8 b to be drawn up through the penetration hole 56 e due to the capillary phenomenon, so as to prevent a cause of gaps between the solder layer 8 b and the insulating layer 53 b and thus avoid the expansion of the spread of the solder layer 8 b. This configuration can improve the reliability and avoid or decrease the insulation failure of the semiconductor device according to the fourth embodiment if a change in temperature is caused.

Fifth Embodiment

A semiconductor device according to a fifth embodiment differs from the semiconductor device according to the first embodiment in including the single semiconductor chip 3 a with no interposers provided between the semiconductor chip 3 a and the printed circuit board 6, as illustrated in FIG. 11 .

The conductive connection between the semiconductor chip 3 a and the printed circuit board 6 is ensured through the post electrodes 51 a to 51 c and 51 j. The printed circuit board 6 includes the insulating layer 61, the conductor layers (the upper conductor layers) 62 a and 62 b deposited on the top surface of the insulating layer 61, and the conductor layers (the lower conductor layers) 63 a and 63 b deposited on the bottom surface side of the insulating layer 61.

The post electrodes 51 a to 51 c for source, among the post electrodes 51 a to 51 c and 51 j, penetrate through the insulating layer 61 and the upper conductor layer 62 a so as to be electrically connected to the upper conductor layer 62 a. The post electrode 51 j for gate penetrates through the insulating layer 61, the upper conductor layer 62 b, and the lower conductor layer 63 b so as to be electrically connected to the upper conductor layer 62 b and the lower conductor layer 63 b.

The insulating layer 61 of the printed circuit board 6 is provided with penetration holes (not illustrated) through which the post electrodes 51 a to 51 c and 51 j penetrate, and penetration holes 64 a and 64 b filled with part of the solder layer 8 a. The penetration holes 64 a and 64 b are located at positions separated from the penetration holes (not illustrated) through which the post electrodes 51 a to 51 c and 51 j penetrate at the equal distances. The other configurations of the semiconductor device according to the fifth embodiment are the same as those of the semiconductor device according to the first embodiment, and overlapping explanations are not repeated below.

The semiconductor device according to the fifth embodiment with the configuration as described above can lead the solder layer 8 a to be drawn up through the penetration holes 64 a and 64 b provided in the insulating layer 61 of the printed circuit board 6 due to the capillary phenomenon, so as to prevent a cause of gaps between the solder layer 8 a and the insulating layer 61 and thus avoid the expansion of the spread of the solder layer 8 a. This configuration can improve the reliability and avoid or decrease the insulation failure of the semiconductor device according to the fifth embodiment if a change in temperature is caused.

The respective penetration holes 64 a and 64 b provided in the insulating layer 61 may be in contact with the penetration holes (not illustrated) through which the post electrodes 51 a to 51 c penetrate. Alternatively, the respective post electrodes 51 a to 51 c may penetrate through the respective penetration holes 64 a and 64 b so that the gaps between the respective post electrodes 51 a to 51 c and the respective penetration holes 64 a and 64 b are filled with part of the solder layer 8 a. In such a case, the upper conductor layer 62 a may be provided with a plurality of recesses to which the other ends of the respective post electrodes 51 a to 51 c are inserted by pressure.

Other Embodiments

As described above, the invention has been described according to the first to fifth embodiments, but it should not be understood that the description and drawings implementing a portion of this disclosure limit the invention. Various alternative embodiments of the present invention, examples, and operational techniques will be apparent to those skilled in the art from this disclosure.

While the respective first to fifth embodiments have been illustrated above with the semiconductor device that is the “1-in-1” power semiconductor module having the functions for a single semiconductor element, the present invention is not limited to this case. For example, the present invention may also be applied to a “2-in-1” power semiconductor module having functions for two semiconductor elements.

The configurations disclosed in the first to fifth embodiments may be combined as appropriate within a range that does not contradict with the scope of the respective embodiments. As described above, the invention includes various embodiments of the present invention and the like not described herein. Therefore, the scope of the present invention is defined only by the technical features specifying the present invention, which are prescribed by claims, the words and terms in the claims shall be reasonably construed from the subject matters recited in the present Specification. 

1. A semiconductor device comprising: an insulated circuit substrate; a semiconductor chip deposited on one of main surfaces of the insulated circuit substrate; a printed circuit board provided to be opposed to the one of the main surfaces of the insulated circuit substrate; an interposer provided between the semiconductor chip and the printed circuit board; and a sealing member provided to seal the semiconductor chip, the interposer, and the printed circuit board, the interposer including a plurality of post electrodes each having one end bonded to the semiconductor chip via a solder layer, an insulating layer provided to be separately opposed to the semiconductor chip and provided with a first penetration hole filled with part of the solder layer, and a conductor layer provided to be opposed to the printed circuit board and connected to another end of each of the post electrodes via the insulating layer.
 2. A semiconductor device comprising: an insulated circuit substrate; a semiconductor chip deposited on one of main surfaces of the insulated circuit substrate; a plurality of post electrodes each having one end bonded to the semiconductor chip via a solder layer; a printed circuit board provided to be opposed to the one of the main surfaces of the insulated circuit substrate; and a sealing member provided to seal the semiconductor chip and the printed circuit board, the printed circuit board including an insulating layer provided to be separately opposed to the semiconductor chip and provided with a first penetration hole filled with part of the solder layer, and a conductor layer connected to another end of each of the post electrodes via the insulating layer.
 3. The semiconductor device of claim 1, wherein the insulating layer is further provided with a plurality of second penetration holes through which the plural post electrodes penetrate.
 4. The semiconductor device of claim 3, wherein the first penetration hole is provided separately from the respective adjacent second penetration holes at equal distances.
 5. The semiconductor device of claim 3, wherein the first penetration hole is in contact with the respective second penetration holes.
 6. The semiconductor device of claim 1, wherein: the insulating layer comprises a plurality of the first penetration holes; the plural post electrodes penetrate through the first penetration holes; and a gap between the respective post electrodes and the respective first penetration holes is filled with part of the solder layer.
 7. The semiconductor device of claim 6, wherein the conductor layer is provided with a plurality of recesses to which the other end of each of the post electrodes is inserted by pressure.
 8. The semiconductor device of claim 2, wherein the insulating layer is further provided with a plurality of second penetration holes through which the plural post electrodes penetrate.
 9. The semiconductor device of claim 8, wherein the first penetration hole is provided separately from the respective adjacent second penetration holes at equal distances.
 10. The semiconductor device of claim 8, wherein the first penetration hole is in contact with the respective second penetration holes.
 11. The semiconductor device of claim 2, wherein: the insulating layer comprises a plurality of the first penetration holes; the plural post electrodes penetrate through the first penetration holes; and a gap between the respective post electrodes and the respective first penetration holes is filled with part of the solder layer.
 12. The semiconductor device of claim 11, wherein the conductor layer is provided with a plurality of recesses to which the other end of each of the post electrodes is inserted by pressure. 